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As part of a larger study on Epsilonproteobacteria carried by wild birds in the city of Valdivia (southern Chile), two curved rod-shaped Gram-stain-negative strains (A82T and WB-40) were recovered from faecal samples and subjected to a taxonomic study. Results of a genus-specific PCR showed that these isolates belonged to the genus Helicobacter. Further identification by 16S rRNA and hsp60 (60 kDa heat-shock protein) gene sequence analysis revealed that they formed a separate phylogenetic clade, different from other known Helicobacter species with 'Helicobacter burdigaliensis' CNRCH 2005/566HT and Helicobacter valdiviensis WBE14T being the most closely related species. This was confirmed by core-genome phylogeny as well as digital DNA-DNA hybridization and average nucleotide identity analyses between the genomes of strains A82T and WB-40 and all other Helicobacter species. The draft genome sequences of A82T and WB-40, obtained by Illumina NextSeq 2000 sequencing, consisted of 1.6 Mb with a G+C content of 31.9-32.0 mol%. The results obtained from the phylogenetic and genomic characterization, together with their different morphological and biochemical features, revealed that these two strains represent a novel species, for which we propose the name Helicobacter ibis sp. nov. with A82T (=LMG 32718T=CCCT 22.04T) as the type strain.

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Helicobacter is a genus of Gram-negative bacteria that colonizes the stomach of humans and dogs, among other mammals. The most frequent species found in the gastric mucosa of man is H. pylori, however, there are other species of Helicobacter in the stomach of humans, such as H. suis, H. bizzozeronii, H. felis, H. salomonis and H. heilmannii sensu stricto, named non H. pylori Helicobacter (NHPH) some of which also colonize the dog's stomach. The detection of NHPH in the stomach mucosa of humans with gastric disease, and in a high percentage of dogs, suggests the possibility that these animals play an important role in the pathogenesis and transmission of infection to man, postulating the path of transmission oral-oral or fecal-oral. The aim of this study was to determine whether people with signs of chronic gastritis who have Helicobacter spp. and who own dogs as pets, share the same species with them. The presence of Helicobacter spp. in gastric samples of 30 people with clinical signs of chronic gastritis and histopathological diagnosis of gastric infection with Helicobacter spp. was analyzed by PCR. The presence of Helicobacter spp. was also studied in the dogs of these people. Then, the species of Helicobacter presented was determined in both. In human gastric samples, H. pylori was the only species found, while in dogs, samples were H. bizzozeronii, H. felis, H. salomonis and H. heilmannii. In this work the same species were not found in dogs and their owners.

Helicobacter es un género bacteriano gram negativo que coloniza el estómago de humanos y perros, entre otros mamíferos. En la mucosa gástrica del hombre la especie más frecuentemente hallada es H. pylori, sin embargo, puede albergar otras especies, como H. suis, H. bizzozeronii, H. felis, H. salomonis y H. heilmannii sensu stricto, denominadas Helicobacter no H. pylori (NHPH), algunas de las cuales colonizan también el estómago del perro. La detección de especies NHPH en la mucosa del estómago de seres humanos con enfermedad gástrica y en un alto porcentaje de perros como mascotas, sugiere la posibilidad de que estos animales jueguen un rol importante en la patogenia y transmisión de la infección al hombre, postulándose la vía de transmisión oral-oral o bien fecal-oral. El objetivo de este trabajo fue determinar si individuos con signos de gastritis crónica que tienen Helicobacter spp. y que poseen perros como mascotas, comparten con ellos las mismas especies. Para ello se estudió por PCR la presencia de Helicobacter spp. en muestras gástricas de 30 pacientes con signos clínicos de gastritis crónica y diagnóstico histopatológico de infección gástrica con Helicobacter spp. También se estudió la presencia de estas bacterias en sus perros para determinar si existe correspondencia en las especies presentes en ambos. La única especie encontrada en humanos fue H. pylori, mientras que en los perros se encontraron H. bizzozeronii, H. felis, H. salomonis y H. heilmannii. En este trabajo no se encontraron las mismas especies en los perros y en sus propietarios.

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•Clinical studies have shown that hepatobiliary diseases of inflammatory and neoplastic origin are associated with Helicobacter infection. •Translocation and the ascending pathway are putative mechanisms for Helicobacter spp to enter the hepatobiliary system. •H. pylori infection has a systemic effect through the activity of pro-inflammatory cytokines, TNF-α, leukotrienes, interferon-ß, interferon-γ, and acute phase proteins. •Histopathological confirmation is needed to present that H. pylori eradication prevents or improves hepatobiliary disease progression. Helicobacter Pylori (H. pylori) is one of the main infectious causes of gastroduodenal diseases, however, its role in developing different extragastric diseases has been proven. The possible involvement of H. pylori in the pathogenesis of cardiovascular, metabolic, neurodegenerative, skin, and hepatobiliary diseases is suggested. The bacterium has been found in tissue samples from the liver, biliary tract, and gallstones of animals and humans. However, the role of H. pylori infection in the pathogenesis of liver and biliary diseases has not been finally established. The histopathological confirmation of the positive effect of H. pylori eradication is needed. In addition, there are discussions on the clinical significance of other Helicobacter species. The review presents the data available for and against the involvement of H. pylori in hepatobi-liary disease development and progression.

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BACKGROUND: Gastric non-Helicobacter pylori helicobacters (NHPH) naturally colonize the stomach of animals. In humans, infection with these bacteria is associated with chronic active gastritis, peptic ulceration and MALT-lymphoma. H. bizzozeronii belongs to these NHPH and its prevalence in children is unknown. CASE PRESENTATION: This case report describes for the first time a NHPH infection in a 20-month-old girl with severe gastric disorders in Mexico. The patient suffered from melena, epigastric pain, and bloating. Gastroscopy showed presence of a Hiatus Hill grade I, a hemorrhagic gastropathy in the fundus and gastric body, and a Forrest class III ulcer in the fundus. Histopathologic examination revealed a chronic active gastritis with presence of long, spiral-shaped bacilli in the glandular lumen. Biopsies from antrum, body and incisure were negative for presence of H. pylori by culture and PCR, while all biopsies were positive for presence of H. bizzozeronii by PCR. Most likely, infection occurred through intense contact with the family dog. The patient received a triple therapy consisting of a proton pump inhibitor, clarithromycin, and amoxicillin for 14 days, completed with sucralfate for 6 weeks, resulting in the disappearance of her complaints. CONCLUSION: The eradication could not be confirmed, although it was suggested by clear improvement of symptoms. This case report further emphasizes the zoonotic importance of NHPH. It can be advised to routinely check for presence of both H. pylori and NHPH in human patients with gastric complains.

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Background: Virulence factors (VF) are bacteria-associated molecules that assist to colonize the host at the cellular level. Bacterial virulence is highly dynamic and specific pathogens have a broad array of VFs. The genus Helicobacter is gram-negative, microaerobic, flagellated, and mucus-inhabiting bacteria associated with gastrointestinal inflammation. To investigate about their pathogenicity, several Helicobacter species have been characterized and sequenced. Since the variability and possible origin of VF in the genus are not clear, our goal was to perform a comparative analysis of Helicobacter species in order to investigate VF variability and their evolutionary origin. Methods: The complete genomes of 22 Helicobacter species available in NCBI were analyzed, using computational tools. We identifyed gain and loss events in VF genes, which were categorized in seven functional groups to determine their most parsimonious evolutionary origin. After verifying the annotation of all VF genes, a phylogeny from conserved VF organized by Helicobacter species according to gastric Helicobacter species (GHS) or enterohepatic (EHS) classification was obtained. Results: Gain and loss analysis of VF orthologous in Helicobacter ssp revealed the most possible evolutionary origin for each gene set. Microevolutionary events in urease and flagella genes were detected during the evolution of the genus. Our results pointed that acquisition of ureases and adherence genes and deletion of cytotoxins in some lineages, as well as variation in VF genes copy number, would be related to host adaptation during evolution of the Helicobacter genus. Our findings provided new insights about the genetic differences between GHS and EHS and their relationship with pathogenicity.

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RESUMEN La información sobre la presentación y los factores predisponentes del síndrome de úlcera gástrica en mulas (SUGM) es escasa en comparación con el síndrome de úlcera gástrica en equinos (SUGE) y asnales. Debido a la naturaleza multifactorial de este síndrome, la helicobacteriosis ha sido estudiada en otras especies. El objetivo de este trabajo fue establecer la presencia de Helicobacter spp. en mucosa gástrica de mulas a través de la prueba rápida de la ureasa (PRU) y de análisis histopatológico. Menos del 27% de las muestras reaccionaron a la PRU, con tiempos prolongados de reacción, y al Agar Urea (prueba de oro), con menor porcentaje de positividad. La histopatología reveló procesos inflamatorios crónicos, sin presencia de bacterias curvoespiraladas. Las PRU no fueron conclusivas en la determinación de Helicobacter spp., comportamiento similar reportado en equinos. Se requieren exámenes diagnósticos más específicos y procedimientos complementarios orientados a explorar por regiones del estómago en la consideración del número de muestras representativas.

ABSTRACT Information on the presentation and predisposing factors of Mule Gastric Ulcer Syndrome (MGUS) is scarce, compared to Equine Gastric Ulcer Syndrome (EGUS) and donkeys. Within the multifactorial nature of this syndrome, helicobacteriosis has been studied in other species. The objective of this work was to establish the presence of Helicobacter spp. in gastric mucosa of mules, through the rapid urease test (RUT) and histopathological analysis. Less than 27% of the samples reacted to RUTs, with prolonged reaction times, and Urea Agar (gold test), with a lower percentage of positivity. Histopathology revealed chronic inflammatory processes, without the presence of curved-spiral bacteria. The RUTs were not conclusive in the determination of Helicobacter spp., a similar behavior reported in horses. More specific diagnostic tests and complementary procedures are required to explore the regions of the stomach in consideration of the number of representative samples.

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The occurrence of Helicobacter spp. and fecal bacterial contamination was investigated in high-altitude environments from the Northeastern Andes of Venezuela. Helicobacter DNA was detected by PCR in streams, drinking and irrigation waters, and one culture from drinking water by the HP enrichment medium for selection of Helicobacter pylori, which displayed 98.98% homology to this pathogen based on 16S rRNA gene sequencing. FISH demonstrated predominant coccoid cells of the target bacteria indicative of the viable but nonculturable (VBNC) state in all water samples and HP cultures. Our work reveals for the first time Helicobacter spp. in waters from one of the highest places in the world. These results, together with the presence of fecal coliforms (2-160 MPN/100 mL) from the headwaters of rivers to drinking and irrigation waters, alert fecal contamination and epidemiological implications in this area of ecological and economic importance for the region.

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The genus Helicobacter defined just over 30 years ago, is a highly diverse and fast-growing group of bacteria that are able to persistently colonize a wide range of animals. The members of this genus are subdivided into two groups with different ecological niches, associated pathologies, and phylogenetic relationships: the gastric Helicobacter (GH) and the enterohepatic Helicobacter (EHH) species. Although GH have been mostly studied, EHH species have become increasingly important as emerging human pathogens and potential zoonotic agents in the last years. This group of bacteria has been associated with the development of several diseases in humans from acute pathologies like gastroenteritis to chronic pathologies that include inflammatory bowel disease, and liver and gallbladder diseases. However, their reservoirs, as well as their routes of transmission, have not been well established yet. Therefore, this review summarizes the current knowledge of taxonomy, epidemiology, and clinical role of the EHH group.

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BACKGROUND: Enterohepatic species of the genus Helicobacter (EHH) are emerging pathogens that have been associated with gastrointestinal and hepatobiliary diseases in humans. However, studies on their pathogenicity are scarce. Galleria mellonella is a recently proposed model for the study of virulence in different pathogens, such as Campylobacter spp. and Helicobacter pylori. Despite this, its usefulness in EHH has not yet been evaluated. Therefore, we determined the pathogenic potential of different EHH species isolated from dogs in this infection model. MATERIALS AND METHODS: Four species of EHH (H. bilis, H. canicola, H. canis, and 'H. winghamensis') isolated from fecal samples from domestic dogs were evaluated. Three strains of each species were inoculated in cohorts of G. mellonella at a concentration of 1 × 107  CFU/mL. Survival curves were determined by the Kaplan-Meier method. In addition, the quantification of melanin, bacterial load in hemolymph, and histopathology were evaluated daily post-infection (pi). RESULTS: G. mellonella larvae are susceptible to EHH infection, exhibiting intra- and inter-species variability. Melanin production became evident from 4 h pi and increased throughout the assay. All species were recovered from the hemolymph after 20 min pi; however, only H. canis could be recovered up to 48 h pi. Histopathology revealed cellular and humoral immune response, evidencing accumulation of hemocytes, nodulation, and melanin deposition in different tissues. CONCLUSION: EHH species carried by dogs have considerable pathogenic potential, being H. canicola the species with the highest degree of virulence. Thus, G. mellonella is a useful model to assess virulence in these emerging pathogens.

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Enterohepatic Helicobacter (EHH) species have been increasingly associated with acute gastroenteritis, inflammatory bowel disease and hepatobiliary diseases in humans. However, their host range and transmission routes are poorly understood. Therefore, the aim of this study was to determine the presence of EHH in healthy dogs using both cultivation-dependent and -independent methods. Three hundred and ninety faecal samples from domestic dogs without gastrointestinal symptoms were analysed between June 2018 and July 2019 in Valdivia (South of Chile). Samples were inoculated on selective medium and in parallel were filtrated over an antibiotic-free blood agar. Both media were incubated in a microaerobic atmosphere at 37°C for 7 days. Colonies were identified by PCR and phylogenetic analysis. A subset of 50 samples (half of them positive for EHH by cultivation and the remaining half negative) was analysed by PCR-Denaturing Gradient Gel Electrophoresis (PCR-DGGE) for direct detection. Cultivation method detected EHH in 15.4% (60/390) of the samples, being the most prevalent species H. canis (5.8%, 23/390) and H. canicola (5.1%, 20/390), followed by H. bilis (3.6%, 14/390) and 'H. winghamensis' (1.3%, 5/390). In contrast, PCR-DGGE method detected Helicobacter DNA in almost all (96%, 48/50) tested samples. On the other hand, the method used also allowed to isolate other Campylobacterales, in fact 44.3% (173/390) of the samples were positive for Campylobacter upsaliensis (43.3%, 169/390) followed by C. jejuni (2.0%, 8/390). Moreover, two strains that presented Campylobacter-like morphology were finally identified as Anaerobiospirillum succiniciproducens. Our results indicate that healthy domestic dogs commonly carry EHH and other Campylobacter species. However, further studies are needed to determine whether and how these Helicobacter and Campylobacter species can be transmitted to humans.

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